title: Silica-lipid hybrid microcapsules: influence of lipid and emulsifier type on in vitro performance.
abstract: This study reports on the physicochemical characterisation and in vitro investigations of macro-porous silica-lipid hybrid (SLH) microcapsules when formulated using various lipids: long-chain triglycerides (LCT), medium-chain triglycerides (MCT), medium-chain mono-, diglycerides (MCMDG); and emulsifiers: anionic lecithin and cationic oleylamine. For the lipophilic compound coumarin 102 (logP=4.09), a complete and immediate in vitro release was attained for the SLH microcapsules under simulated intestinal sink conditions. The in vitro digestion study of various types of SLH microcapsules demonstrates: (i) reduced variability and enhanced lipid digestibility for the MCMDG-based microcapsules (i.e. 90-100% lipolysis) in comparison with an equivalent lipid solution and emulsion (50-90% lipolysis); and (ii) more controllable digestion kinetics for the LCT-based microcapsules which produce a lipolysis rate higher than that of a lipid solution but lower than that of a lipid emulsion. The drug phase partition results show approximately 5- to 17-fold increase in the drug solubilisation degree resulting from the digestion of MCT and MCMDG-based microcapsules (116 μg/mL), and LCT-based microcapsules (416 μg/mL) in comparison with the blank micellar medium (24 μg/mL). In conclusion, the SLH microcapsules could be tailored to manipulate the digestion patterns of both medium- and long-chain lipids in order to maximise the drug solubilisation capacity.
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, SA 5095, Australia.
authors.forename: Li Hui
authors.initials: LH
authors.lastname: Lim
authors.forename: Angel
authors.initials: A
authors.lastname: Tan
authors.forename: Spomenka
authors.initials: S
authors.lastname: Simovic
authors.forename: Clive A
authors.initials: CA
authors.lastname: Prestidge
mesh_terms: D000588:Amines / Q000737:chemistry; D002214:Capsules; D003374:Coumarins / Q000008:administration & dosage* / Q000737:chemistry; D004075:Diglycerides / Q000737:chemistry*; D016503:Drug Delivery Systems; D004655:Emulsions; D005079:Excipients / Q000737:chemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D054709:Lecithins / Q000737:chemistry; D008066:Lipolysis; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D012995:Solubility; D014280:Triglycerides / Q000737:chemistry*
chemical_list: D000588:Amines; D002214:Capsules; D003374:Coumarins; D004075:Diglycerides; D004655:Emulsions; D005079:Excipients; D054709:Lecithins; D014280:Triglycerides; D012822:Silicon Dioxide; C008703:oleylamine